Tumor Necrosis Factor-α Promoter Polymorphisms in Mexican Patients With Spondyloarthritis

The synergistic role of TNFA - 308G/A and IL10 - 1082A/G polymorphisms in ankylosing spondylitis

OBJECTIVE

Genetic polymorphisms of the cytokine genes could alter their protein expression, thus creating a genetic basis of dysregulated cytokine production and function, which render them as excellent candidates predisposing to autoimmune diseases. We investigated single nucleotide polymorphisms (SNPs) at TNFA - 308G/A and IL10 - 1082A/G locus to identify their involvement, separately or in combination, in determining susceptibility to ankylosing spondylitis (AS), as well as their functional connections with relevant serum cytokines and associations with disease characteristics.

METHODS

Eighty-one AS patients and 215 healthy controls were genotyped by polymerase chain reaction-based method; 76 patients and sex-matched controls were also subjected to analysis of serum TNF-α and IL-10 levels by enzyme-linked immunosorbent assay.

RESULTS

We identified the homozygous genotype GG of the TNFA-308 significantly more common in patients than controls; whereas the - 308 minor A-allele predicts a threefold decreased risk against developing AS and shows associations with milder radiographic spinal impairments and functional limitations. This protective effect was multiplied by fivefold in synergistic interaction with the homozygous - 1082AA genotype of the IL10 which acts as a modifying factor, since IL10 - 1082A/G SNPs by itself did not have a significant impact on AS genetic susceptibility. In comparison with controls, AS patients had significantly elevated mean serum TNF-α levels and decreased mean IL-10 concentrations not restricted to any particular genotype.

CONCLUSION

TNFA - 308 A-allele is essential for reducing susceptibility to AS, with a considerable synergistic protective effect of the combined TNF-α - 308 (GA/AA)/IL-10 - 1082AA genotypes. In addition, the presence of this variant allele is associated with more benign clinical phenotype of the disease. No conclusive statements on the functional relevance of both gene variants on cytokines production should be made.

A meta-analysis for association of TNF-α -308G>A polymorphism with susceptibility to Ankylosing Spondylitis

Objective

We performed a meta-analysis of all eligible studies on the association of TNF-α -308G>A polymorphism with risk of Ankylosing spondylitis (AS).

Methods

A comprehensive literature research was performed in online databases.

Results

A total of 28 studies with 4489 cases and 5919 controls were included. Pooled ORs showed a significant association between TNF-α -308G>A polymorphism and risk of AS. Moreover, stratified analysis by ethnicity showed a significant association between TNF-α -308G>A polymorphism and AS risk in Asians, Caucasians and Mixed populations, but not in Chinese population.

Conclusion

This meta-analysis suggested that the TNF-α -308G>A polymorphism was associated with AS risk.

Influence of IL10 (rs1800896) Polymorphism and TNF-α, IL-10, IL-17A, and IL-17F Serum Levels in Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic autoimmune inflammatory disease that mainly affects the axial and sacroiliac joints. Single-nucleotide polymorphisms (SNPs) in genes encoding cytokines have been associated with AS, which can interfere with the production of these cytokines and contribute to the development of AS. In order to contribute to a better understanding of the pathology of AS, our objective was to investigate a possible association of the IL10 −1082 A>G SNP (rs1800896) with AS and to evaluate the serum levels of TNF-α, IL-10, IL-17A, and IL-17F in AS patients and controls comparing them with their respective genotypes (TNF rs1800629, IL10 rs1800896, IL17A rs2275913, and IL17F rs763780). Patients and controls were selected from the Maringá University Hospital and the Maringá Rheumatism Clinic, in Paraná State, Southern Brazil, and they were diagnosed by the ASAS Criteria. In total, 149 patients and 169 controls were genotyped for the IL10 −1082 A>G polymorphism using a polymerase chain reaction with sequence specific primers (PCR-SSP); the measurement of TNF-α serum levels was performed through the immunofluorimetric test and IL-10, IL-17A, and IL-17F using an ELISA test. There was a high frequency of the IL10 −1082 G allele in AS patients compared with controls with an odds ratio of 1.83 and 95% confidence interval of 1.32 to 2.54, and a significant difference in the genotype frequencies of the IL10 −1082 A/G+G/G between patients and healthy controls, with an odds ratio of 3.01 and 95% confidence interval of 1.75 to 5.17. In addition, increased serum levels of IL-10 were observed in AS patients: 2.38 (IQR, 0.91) pg/ml compared with controls 1.72 (IQR 0.93) pg/ml (P = 0.01). Our results also showed an association between IL17F rs763780 C/T+T/T genotypes and increased serum levels of IL-17F in patients with AS and also in controls. We can conclude that patients with the A/G and G/G genotypes for −1082 A>G (rs1800896) in the IL10 gene are three times more likely to develop AS, that the serum level of IL-10 was higher in AS patients and that the IL17F rs763780 polymorphism can affect the levels of IL-17F in the serum of patients and controls in the same way.

Lack of association between TNF polymorphism and ankylosing spondylitis susceptibility in HLA-B27-positive population: a meta-analysis

OBJECTIVE

Human leukocyte antigen (HLA)-B27 plays a crucial role in the pathogenesis of AS. TNF polymorphisms have been reported to be associated with AS susceptibility, but the results of these previous studies have been inconsistent. The aim of this study was to explore whether TNF polymorphism is associated with AS susceptibility in HLA-27-positive population.

METHODS

Our search was done in the Pubmed, Embase, and Cochrane databases (up to March 2020). The pooled and individual odds ratios (ORs) with 95% confidence intervals (CIs) of the minor allele of each locus were presented to assess the associations between TNF polymorphisms and AS in HLA-B27-positive population.

RESULTS

Ten studies from 8 articles were included in this meta-analysis. In the population of HLA-B27-positive patients and random healthy controls, there were statistical significance in the evaluation of association between the minor allele of TNF-238, -308, -857, -1031 and -863 and AS susceptibility, respectively. In the population of HLA-B27-positive patients and HLA-B27-positive healthy controls, there were no statistical differences in the comparison of minor allele of with their respective major allele in the fixed model.

CONCLUSIONS

There was no association of the TNF polymorphisms with AS in the HLA-B27-positive AS group and HLA-B27-positive control group. Polymorphisms of TNF-238, -308, -857, -1031, -863 were associated with AS susceptibility in the HLA-B27-positive AS patients and random control population. Other gene SNPs except TNF may play an important role in AS susceptibility in HLA-B27-positive population.

The association of polymorphisms in TNF and ankylosing spondylitis in common population: a meta-analysis

BACKGROUND

Studies investigating the association between the polymorphisms in TNF and ankylosing spondylitis have been reported the conflicting results. Here we performed a meta-analysis based on the evidence available from the literature up-to-date to further clarify this relationship.

METHODS

Our systematic search was done in the PubMed, Embase and Cochrane databases (up to March 2020). The pooled and individual odds ratios (ORs) with 95% confidence intervals (CIs) of the minor allele of each locus were presented to assess the associations between TNF polymorphisms and AS in different ethnicities in common population.

RESULTS

Seventeen studies, consisting of seven European studies, eight East Asian studies and two Latin-American studies, were included in this meta-analysis. In the total population, the A allele in TNF-238 (OR = 0.702, 95%CI = 0.506-0.973, p = 0.034) and TNF-308 (OR = 0.638, 95%CI = 0.507-0.804, p = 0.000), the C allele in TNF-1031 (OR = 0.594, 95%CI = 0.446-0.791, p = 0.000), the T allele in TNF-850 (OR = 3.462, 95%CI = 1.764-6.798, p = 0.000) and rs769178 (OR = 2.593, 95%CI = 2.175-3.091, p = 0.000) were significantly associated with AS susceptibility. There were no significant association between the minor alleles of TNF-376, TNF-857, TNF-863 and AS susceptibility. There are inconsistent results in the Latin-American population and East Asian population with those in the total population.

CONCLUSIONS

Our meta-analysis suggests that TNF-α polymorphisms at positions - 238, - 308, - 850, - 1031 and rs769178 could have an influence on ankylosing spondylitis susceptibility in the total population. But there is no association of the TNF-376, TNF-857, TNF-863 polymorphisms with ankylosing spondylitis. Some results in the subgroups are not consistent with those in the total population.

Associations of Tumor Necrosis Factor Alpha Gene Polymorphisms and Ankylosing Spondylitis Susceptibility: A Meta-analysis Based on 35 Case-control Studies

Background: Scores of studies on tumor necrosis factor alpha (TNF-α) gene polymorphisms and AS have been performed with inconsistent results. The purpose of this study was to provide some more convincing evidence on the associations of TNF-a polymorphisms and AS by using a meta-analysis approach.Methods: Potentially relevant studies were identified from Web of Science, PubMed, EMBASE, Wanfang, and CNKI from inception to March 5, 2020. Newcastle-Ottawa Scale (NOS) was utilized to appraise the quality of included studies. Odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated to assess the strength of the associations under five genetic models.Results: Thirty-five studies with 37 independent cohorts in total were included in the meta-analysis. Based upon NOS, eligible studies were in moderate- to high quality. The merged data suggested rs1799724 polymorphisms were significantly correlated with a reduced risk of AS (C vs. T, OR = 0.55, 95%CI 0.38-0.79, P < .001, P_Bon = 0.005, P_FDR = 0.003). Subgroup analysis by ethnicity indicated that rs1800629 polymorphism significantly increased the risk of AS in Caucasians and decreased the risk of AS in mixed populations. Besides, rs361525 and rs1800630 polymorphisms conferred to an elevated risk of AS, and rs1799724 conferred to a reduced risk of AS in Asians.Conclusions: This study suggests that rs1800629 polymorphism is associated with an increased AS risk in Caucasians, rs361525 and rs1800630 polymorphisms are linked to an elevated AS susceptibility in Asians.

Association between cytokine gene polymorphisms and ankylosing spondylitis susceptibility: a systematic review and meta-analysis

PURPOSE OF THE STUDY

The aim of this study was to perform a meta-analysis to derive precise estimation of the association of interleukin-23 receptor (IL-23R), IL-1 receptor 2 (IL-1R2), IL-12 beta (IL-12B), IL-10 and tumour necrosis factor (TNF)-α polymorphisms with ankylosing spondylitis (AS) susceptibility.

STUDY DESIGN

A systematic literature search was conducted to identify the relevant studies. Pooled OR with 95% CI was calculated to assess the strength of the association in a fixed or random-effects model.

RESULTS

A total of 13 917 cases and 19 849 controls in 43 eligible studies were included in the meta-analysis. Seventeen single-nucleotide polymorphisms (SNPs) in the abovementioned five cytokine genes were evaluated. The results indicate that the nine SNPs (rs11209026, rs1004819, rs10489629, rs11465804, rs1343151, rs11209032, rs1495965, rs7517847, rs2201841) of IL-23R are associated with AS susceptibility in all study subjects in the allelic model. Moreover, stratification by ethnicity identified a significant association between seven SNPs of IL-23R and AS susceptibility in Europeans and Americans, but not in Asians. In addition, the IL-10-819  C/T and TNF-α-857 C/T polymorphisms also confer susceptibility to AS, especially in Asian population.

CONCLUSION

The results suggested that the genetic susceptibility for AS is associated with the nine SNPs of IL-23R in overall population. In the subgroup analysis, significant associations were shown in European and American population, but not in Asian population. Our results also suggest that IL-10-819  C/T and TNF-α-857 C/T polymorphism might be associated with AS risk, especially in Asian population.

Influence of TNF and IL17 Gene Polymorphisms on the Spondyloarthritis Immunopathogenesis, Regardless of HLA-B27, in a Brazilian Population

Background and Objectives

Spondyloarthritis (SpA) represents a heterogeneous group of immune-mediated inflammatory diseases that have overlapping clinical features, genetic predisposition, and pathogenic mechanisms. Hence, we investigated, through a case-control study, whether single-nucleotide polymorphisms of TNF and IL17 genes are associated with SpA, ankylosing spondylitis (AS), and psoriatic arthritis (PsA) in a mixed Brazilian population.

Methods

Genotyping of TNF-308 (rs1800629), TNF-238 (rs361525), IL17A (rs2275913), IL17F (rs763780), and HLA-B27 polymorphisms was performed in 243 patients with SpA and 210 controls from Southern Brazil using SSOP-Luminex (One Lambda) and PCR-SSP assays.

Results

Significant associations were confirmed between the HLA-B27 marker and SpA, AS, and PsA diseases. While TNF-308 (rs1800629) AA/GA, IL17A (rs2275913) AA/GA, and IL17F (rs763780) CC/TC genotype frequencies were associated, in the dominance inheritance model, with SpA and AS, regardless of gender, the presence of HLA-B27, TNF-238 (rs361525) GA/AA, IL17A (rs2275913) AA/GA, and IL17F (rs763780) genotypes was associated with PsA.

Conclusion

In this Brazilian population, TNF and IL17 gene polymorphisms responsible for the expression of important inflammatory cytokines were associated with overall SpA, and, specifically, with AS and PsA, regardless of gender and HLA-B27. However, future larger studies with different ethnicities may be necessary to confirm these genetic associations.

TNF-α gene polymorphisms and expression

Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine with an important role in the pathogenesis of several diseases. Its encoding gene is located in the short arm of chromosome 6 in the major histocompatibility complex class III region. Most of the TNF-α gene polymorphisms are located in its promoter region and they are thought to affect the susceptibility and/or severity of different human diseases. This review summarizes the data related to the association between TNF-α gene and its receptor polymorphisms, and the development of autoimmune diseases. Among these polymorphisms the -308G/A TNF-α promotor polymorphism has been associated several times with the the development of autoimmune diseases, however some discrepant results have been recorded. The other TNF-α gene polymorphisms had little or no association with autoimmune diseases. Current results about the molecules controlling TNF-α expression are also presented. The discrepancy between different records could be related partly to either the differences in the ethnic origin or number of the studied individuals, or the abundance and activation of other molecules that interact with the TNF-α promotor region or other elements.

The roles of genetic factors in uveitis and their clinical significance

BACKGROUND

Uveitis is a diverse group of intraocular inflammatory disease and is a significant cause of visual loss worldwide. Recent studies have identified various endogenous immune mechanisms and genetic factors that are involved in the pathogenesis of uveitis. This review provides an overview on the role of genetics in the development and clinical course of uveitis.

METHODS

PUBMED was used for literature search, and articles published from 1970 to 2012 that evaluated the genetic associations and mechanisms involved in the development and clinical features of uveitis were included.

RESULTS

Studies have demonstrated associations between various genetic factors and the development and clinical course of intraocular inflammatory conditions. Genes involved included genes expressing interleukins, chemokines, chemokine receptors, and tumor necrosis factor and genes involved in complement system, oxidation, and other intracellular molecular pathways.

CONCLUSION

Multiple genetic factors play important roles in the pathogenesis of uveitis and may influence the clinical course of uveitis. Further studies to investigate the genetic mechanisms of uveitis might identify additional genetic associations and might have the potential for identifying novel therapeutic targets in the treatment of intraocular inflammation.

The tumor necrosis factor α (-308 A/G) polymorphism is associated with cystic fibrosis in Mexican patients

Environmental and genetic factors may modify or contribute to the phenotypic differences observed in multigenic and monogenic diseases, such as cystic fibrosis (CF). An analysis of modifier genes can be helpful for estimating patient prognosis and directing preventive care. The aim of this study is to determine the association between seven genetic variants of four modifier genes and CF by comparing their corresponding allelic and genotypic frequencies in CF patients (n = 81) and control subjects (n = 104). Genetic variants of MBL2 exon 1 (A, B, C and D), the IL-8 promoter (-251 A/T), the TNFα promoter (TNF1/TNF2), and SERPINA1 (PI*Z and PI*S) were tested in CF patients and control subjects from northeastern Mexico by PCR-RFLP.

RESULTS

The TNF2 allele (P = 0.012, OR 3.43, 95% CI 1.25-9.38) was significantly associated with CF under the dominant and additive models but was not associated with CF under the recessive model. This association remained statistically significant after adjusting for multiple tests using the Bonferroni correction (P = 0.0482). The other tested variants and genotypes did not show any association with the disease.

CONCLUSION

An analysis of seven genetic variants of four modifier genes showed that one variant, the TNF2 allele, appears to be significantly associated with CF in Mexican patients.

Association of TNF-α polymorphism with prediction of response to TNF blockers in spondyloarthritis and inflammatory bowel disease: a meta-analysis

Aim: To explore whether TNF-α promoter -308 A/G and -857 C/T polymorphisms have an association with responsiveness to TNF blockers in spondyloarthritis and inflammatory bowel disease. Methods: A meta-analysis was performed. Pooled odds ratios (ORs) and 95% CIs were calculated. Results: Six relevant studies with a total of 211 spondyloarthritis patients and 392 inflammatory bowel disease patients were included. The results showed that the common allele (G and C, respectively) showed a better responsiveness than the minor allele (A and T, respectively). The -308 G/G genotype (OR: 2.31; 95% CI: 1.36–3.91; p = 0.002) and -857 C/C genotype (OR: 3.66; 95% CI: 1.35–9.92; p = 0.01) responded better to therapy, which was different from the results of some studies included. Conclusion: Individuals with the TNF-α-308 G allele and -857 C allele showed better anti-TNF-α treatment responses than those with the TNF-α-308 A allele and -857 T allele. The -308 G/G genotype and -857 C/C genotype are predictors of good response.

Original submitted 30 May 2013; Revised submitted 25 July 2013

Ankylosing spondylitis: from cells to genes

Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown etiology, though it is considered an autoimmune disease. HLA-B27 is the risk factor most often associated with AS, and although the mechanism of involvement is unclear, the subtypes and other features of the relationship between HLA-B27 and AS have been studied for years. Additionally, the key role of IL-17 and Th17 cells in autoimmunity and inflammation suggests that the latter and the cytokines involved in their generation could play a role in the pathogenesis of this disease. Recent studies have described the sources of IL-17 and IL-23, as well as the characterization of Th17 cells in autoimmune diseases. Other cells, such as NK and regulatory T cells, have been implicated in autoimmunity and have been evaluated to ascertain their possible role in AS. Moreover, several polymorphisms, mutations and deletions in the regulatory proteins, protein-coding regions, and promoter regions of different genes involved in immune responses have been discovered and evaluated for possible genetic linkages to AS. In this review, we analyze the features of HLA-B27 and the suggested mechanisms of its involvement in AS while also focusing on the characterization of the immune response and the identification of genes associated with AS.

The association between tumor necrosis factor alpha promoter polymorphisms and ankylosing spondylitis: a meta-analysis

BACKGROUND

Studies investigating the association between tumor necrosis factor (TNF)-alpha promoter polymorphisms and ankylosing spondylitis have reported conflicting results. We here performed a meta-analysis based on the evidence currently available from the literature to make a more precise estimation of this relationship.

METHODS

We performed a systematic search of the National Library of Medline and Embase databases before January 2013. This meta-analysis included 14 case-control studies, which included 1607 ankylosing spondylitis cases and 1910 controls.

RESULTS

The combined results based on all studies showed that ankylosing spondylitis cases had a significantly lower frequency of -308GA [OR (codominant model)=0.81, 95% CI=0.66, 0.99, P=0.04], -857CT [OR (codominant model)=0.55, 95% CI=0.32, 0.94, P=0.03], -863AA [OR (codominant model)=0.11, 95% CI=0.01, 0.94, P=0.04], -863CA [OR (codominant model)=0.32, 95% CI=0.18, 0.58, P<0.001], and -1031TC [OR (codominant model)=0.44, 95% CI=0.25, 0.77, P=0.004] genotype. However, ankylosing spondylitis cases had a significantly higher frequency of -238AA [OR (recessive model)=7.43, 95% CI=3.66, 15.05, P<0.001] and -850TT [OR (recessive model)=2.49, 95% CI=1.16, 5.34, P=0.02; OR (codominant model)=2.83, 95% CI=1.28, 6.25, P=0.01] genotype. In the subgroup analysis by race, we found that ankylosing spondylitis cases had a significantly higher frequency of -238AA [OR (recessive model)=7.43, 95% CI=3.66, 15.05, P<0.001] genotype in Caucasians and lower frequency of -857CT [OR (codominant model)=0.53, 95% CI=0.30, 0.94, P=0.03] in Asians.

CONCLUSIONS

Our meta-analysis suggests that TNF-alpha promoter polymorphisms at positions -238, -308, -850, -857, -863 and -1031 could have a small influence on ankylosing spondylitis susceptibility. But there is a lack of association of the TNF-alpha-376G/A and -646G/A polymorphisms with ankylosing spondylitis.

TNF-α -857 and -1031 polymorphisms predict good therapeutic response to TNF-α blockers in Chinese Han patients with ankylosing spondylitis

AIM

To evaluate whether polymorphisms at -857, -1031, -308 and -238 positions of the TNF-α gene influence response to TNF-α-blocker therapy in Chinese Han patients with ankylosing spondylitis.

PATIENTS & METHODS

A total of 106 patients with ankylosing spondylitis were recruited and genotyped for -857, -1031, -308 and -238 TNF-α gene polymorphisms. In total, 32 received infliximab and 74 received a recombinant human TNF-α receptor II-IgG Fc fusion protein (rhTNFR-Fc). At the end of 12 weeks, patients were assessed using the Assessment of SpondyloArthritis International Society (ASAS) 20, 40, 50 and 70 criteria.

RESULTS

Polymorphisms at -308 and -238 did not affect therapeutic response. The -857 C/C genotype (p = 0.0021) responded better to therapy. The -1031 T/T genotype (p = 0.0004) showed better outcome.

CONCLUSION

In Chinese Han ankylosing spondylitis patients, polymorphisms at the -308 and -238 positions of the TNF-α gene are unable to predict TNF-α-blocker response; however, -857 C/C and -1031 T/T genotypes have the ability to predict good response.

Association between transforming growth factor-α polymorphism and ankylosing spondylitis: a meta-analysis update

OBJECTIVES

The reported results of the relationship between genetic polymorphisms of tumor necrosis factor (TNF)-α -238, -308 locus and ankylosing spondylitis (AS) susceptibility are not always consistent. This article aims to perform a meta-analysis to collect all the relevant studies to date to further clarify the relationship between those genetic polymorphisms and AS.

METHODS

A computer search was carried out up to September 2011 for literature pertaining to AS and TNF-α polymorphisms.

RESULTS

Twenty-two articles were included, with 2,506 cases of AS and 3,023 normal controls. We searched for genotypes A allele vs. G allele, AA vs. GG + GA, and GA + AA vs. GG in a fixed/random-effects model. The effect summary odds ratios (ORs) and 95 % confidence intervals (CIs) were obtained, which shows there was no association between genetic polymorphisms and AS. As the heterogeneity was observed, in a subgroup analysis by ethnicity, the degree of risk of two genes with AS susceptibility was similar in populations of European and Asian origin. For the human leukocyte antigen (HLA)-B27+ population, results were not statistically significant.

CONCLUSION

ORs of various comparisons indicate that there is no association between TNF-α -238, -308 polymorphisms and AS susceptibility in the overall population and in the subgroup of Asian and non-Asian descent.

Tumor necrosis factor-α -308G/A polymorphism is associated with active vitiligo vulgaris in a northeastern Mexican population

Vitiligo is a skin disease characterized by depigmentation. Its etiopathogenesis is unclear, but it has been associated with autoimmune processes. Gene polymorphisms in the tumor necrosis factor-α (TNF-α) have been associated with several imflammatory diseases. In particular, the -308G/A polymorphism in the gene promoter region has been reported to be associated with increased plasma levels of TNF-α and with an increased risk to develop autoimmune diseases. To date, this polymorphism has not been associated with vitiligo. To assess a possible association between the TNF-α -308G/A and vitiligo vulgaris (VV), 198 vitiligo patients and 395 control subjects were recruited for the study. A complete demographic and clinical profile of each case was registered to analyze the possible risk factors of vitiligo. Genomic DNA isolated from peri pheral blood was subjected to PCR-RFLP for genotyping of the TNF-α -308G/A polymorphism. Causal associations were determined by χ(2) test and their respective OR was assessed in a 2×2 contingency table. When population variables of type of vitiligo, gender, age of disease onset, and active disease status were considered, an association between active VV and the TNF-α GA genotype was found (P=0.0295, OR=2.0; 95% CI 1.01-3.93). All other variables were irrelevant to vitiligo. Our data suggest a possible association between the TNF-α -308 GA genotype and the active form of VV in a Mexican population.

Relation of HLA-B27, Tumor Necrosis Factor-α Promoter Gene Polymorphisms, and T Cell Cytokine Production in Ankylosing Spondylitis — A Comprehensive Genotype-Phenotype Analysis from an Observational Cohort

Objective.

In a pilot study, a distinct T cell cytokine pattern associated with HLA-B27 status and a tumor necrosis factor-α (TNF-α) promoter gene polymorphism was found at –308 (TNF–308). The objective of our study was to assess these associations in a different cohort of patients with ankylosing spondylitis (AS) and to evaluate any effect on clinical measurements.

Methods.

Peripheral T cell cytokine production of patients with AS (n = 121) from the German Spondyloarthritis Inception Cohort was assessed by flow cytometry and correlated with HLA-B27, TNF–238, and TNF–308, and with clinical measurements.

Results.

In HLA-B27-positive, anti-TNF-naive patients with AS, the percentages of TNF-α-producing (5.02%) and interleukin 10-producing (0.31%) CD8+ cells were significantly lower in comparison to HLA-B27-negative patients (9.52%, p = 0.048, and 0.46%, p = 0.037, respectively). A nonsignificant trend was found for a lower production of TNF-α by CD4+ and interferon-γ by both CD4+ and CD8+ T cells, as compared to HLA-B27-negative patients with AS (p > 0.05 for all comparisons). The A allele at TNF–308 was associated with a lower percentage of TNF-α-producing CD4+ T cells. No significant correlations were found between clinical or radiological measurements and cytokine production or with TNF-α promoter gene polymorphisms.

Conclusion.

Modulation of T cell cytokines by HLA-B27 might play a role in AS pathogenesis in B27-positive individuals. No conclusive data were obtained for the TNF–308 polymorphism on cytokine production, and no effect of cytokines or genetic polymorphisms on clinical manifestations was observed.

A pilot study of the association of tumor necrosis factor alpha polymorphisms with psoriatic arthritis in the Romanian population

Tumor necrosis factor alpha (TNF-alpha) is an important pro-inflammatory cytokine implicated in the pathogenesis of psoriatic arthritis. We have performed a case-control association study of three TNF-alpha gene polymorphisms in a group of Romanian psoriatic arthritis patients versus ethnically matched controls. A second group of patients with undifferentiated spondyloarthritis was used in order to look for similarities in the genetic background of the two rheumatic disorders. The −857C/T polymorphism was associated with susceptibility to psoriatic arthritis in our population at the individual level (p = 0.03, OR 1.65, 95% CI 1.05–2.57) and in combined haplotypes with the −238G/A and −308G/A SNPs. Regarding the investigated polymorphisms and derived haplotypes, no potential association was found with the susceptibility to undifferentiated spondyloarthritis in Romanian patients.

Tumor necrosis factor alpha -308 gene locus promoter polymorphism: an analysis of association with health and disease

Tumor necrosis factor-alpha (TNF-alpha) is a potent immunomediator and proinflammatory cytokine that has been implicated in the pathogenesis of a large number of human diseases. The location of its gene within major histocompatibility complex and biological activities has raised the possibility that polymorphisms within this locus may contribute to the pathogenesis of wide range of autoimmune and infectious diseases. For example, a bi-allelic single nucleotide substitution of G (TNFA1 allele) with A (TNFA2 allele) polymorphism at -308 nucleotides upstream from the transcription initiation site in the TNF-alpha promoter is associated with elevated TNF-alpha levels and disease susceptibilities. However, it is still unclear whether TNF-alpha -308 polymorphism plays a part in the disease process, in particular whether it could affect transcription factor binding and in turn influence TNF-alpha transcription and synthesis. Several studies have suggested that TNFA2 allele is significantly linked with the high TNF-alpha-producing autoimmune MHC haplotype HLA-A1, B8, DR3, with elevated serum TNF-alpha levels and a more severe outcome in diseases. This review discusses the genetics of the TNF-alpha -308 polymorphism in selected major diseases and evaluates its common role in health and disease.

Lack of association of TNF-alpha promoter polymorphisms with ankylosing spondylitis: a meta-analysis

OBJECTIVES

Genetic factors, in addition to the HLA-B27, could play a role in the pathogenesis of AS. TNF-alpha promoter polymorphisms have been reported to be associated with AS susceptibility, but the results of these previous studies have been inconsistent. The aim of this study was to explore whether TNF-alpha promoter polymorphisms confer susceptibility to AS.

METHODS

We conducted a random effect meta-analysis on the association of the A/A genotype (the recessive effect), the A/A + A/G genotype (the dominant effect) and the A allele of the TNF-alpha -308 and -238 polymorphisms with AS.

RESULTS

Eight studies, consisting of seven European studies and one Latin American study, were included in this meta-analysis. Any association between AS and the TNF-alpha -308 A allele was not found [odds ratio (OR) = 0.911; 95% CI 0.512, 1.286; P = 0.636; I(2) = 73.8]. There was also no association of the TNF-alpha -308 AA and AA+AG genotypes with AS. Meta-analysis of the TNF-alpha -238 polymorphisms showed no association with AS (OR for A allele = 0.930; 95% CI 0.498, 1.737; P = 0.821; I(2) = 71.6). Subgroup analysis by ethnicity and HLA-B27 positivity did not change the results for the association of the TNF-alpha -308 and -238 polymorphisms with AS.

CONCLUSIONS

This meta-analysis including 2247 subjects has shown that there is a lack of association of the TNF-alpha -308 A/G and -238 A/G polymorphisms with AS.

Tumor necrosis factor-alpha is a common genetic risk factor for asthma, juvenile rheumatoid arthritis, and systemic lupus erythematosus in a Mexican pediatric population

There is a great deal of evidence that points to the association of the tumor necrosis factor-alpha (TNF-alpha) gene as a common genetic factor in the pathogenesis of diseases that are caused by inflammatory and/or autoimmune etiologies. Two single nucleotide polymorphisms (SNPs) identified in the TNF-alpha promoter region have been associated with disease susceptibility and severity. We investigated whether -308G/A and -238G/A TNF-alpha polymorphisms were associated with asthma, systemic lupus erythematosus (SLE), and juvenile rheumatoid arthritis (JRA) in a pediatric Mexican population. In a case-control study of 725 patients (asthma: 226, JRA: 171, and SLE: 328) and 400 control subjects, the participants were analyzed using the allelic discrimination technique. The genotype distribution of both TNF-alpha polymorphisms was in Hardy-Weinberg equilibrium in each group. However, there were significant differences in the allele frequency of TNF-alpha-308A between the patients and the healthy controls. This allele was detected in 2.9% of the controls, 6.0% of asthmatic and JRA patients (p = 0.002 and p = 0.0086), and 6.7% of SLE patients (p = 0.00049); statistical significance was maintained after ancestry stratification (asthma: p = 0.0143, JRA: p = 0.0083, and SLE: p = 0.0026). Stratification by gender showed that the risk for the -308A allele in asthma and JRA was greater in females (OR = 4.16, p = 0.0008 and OR = 4.4, p = 0.0002, respectively). The TNF-alpha -238A allele showed an association only with JRA in males (OR = 2.89, p = 0.004). These results support the concept that the TNF-alpha gene is a genetic risk factor for asthma, SLE, and JRA in the pediatric Mexican population.